TR201901295T4 - Non-woven composite with microfibre - Google Patents

Abstract

The invention relates to a microfibre composite nonwoven fabric comprising a first and a second fiber component arranged in alternating layers, wherein at least one first layer A comprises the first fiber component in the form of composite filaments produced according to the melt spinning method and laid into a fibrous material. The composite fibers are at least partially split and stabilized into elementary filaments with an average linear density of less than 0.1 dtex, preferably between 0.03 dtex and 0.06 dtex, above the first layer A. At least one layer B is arranged, where layer B consists of the second fiber component in the form of fibers with an average linear density of 0.1 to 3 dtex, laid and stabilized as a fibrous material, at least one second layer A being of layer B It was arranged on.

Description

DESCRIPTION MICROFIBER NON-WOVEN COMPOSITE Technical Area The textile physical properties of surfaced strips can be controlled by the chemical and textile physical properties of the fibers or filaments that form them. Here, the fiber- or filament raw materials are selected according to the desired chemical or physical properties, such as their colorability, chemical resistance, thermal deformability, their dirt absorption or adsorption ability. The modulus and strength-elongation properties of the fibers or filaments depend, among other things, on their material properties, which can be controlled by the choice of the degree of crystallization and/or orientation and the cross-sectional geometry, in order to influence the bending rigidity, force adsorption or specific surface areas of the individual fibers or filaments. The total of the textile physical properties of the fibers or filaments that make up a two-dimensional textile structure is also controlled by the weight per unit area. For many purposes, two-dimensional textile structures must meet a large number of requirements, and it is often difficult to ensure that these requirements are compatible with each other. Thus, microfibrous nonwoven fabrics must have a high life span, as well as good usability, good cleaning efficiency, good resistance to mechanical wear and/or a certain water balance.

State of the art One possibility to combine various properties within a two-dimensional structure is to combine different types of fibers with each other, while choosing the production method of the two-dimensional product (e.g. as a woven or knitted product or as a non-woven fabric).

Thus, woven fabrics, knits or tricots containing coarse fibres combined with microfibres offer good durability and at least initially satisfactory handling properties. However, the disadvantage of these two-dimensional structures is that their production is more laborious than that of nonwoven fabrics. In addition, knits in particular have an insufficient retention capacity for microfibres. Thus, after approximately 400 industrial washing cycles (according to DIN EN ISO 155797), it was found that the microfibre content was almost completely eliminated. This manifests itself in a significant deterioration of handling properties such as usability, skin sensitivity, cleaning efficiency or water balance.

Nonwoven fabrics containing microfibers are much easier to manufacture than woven, knitted or tricot fabrics. Nonwoven fabrics are structures consisting of fibers of limited length (staple fibers), filaments of all types and origins (continuous fibers) or cut yarns, combined and bonded in any way to form a fibrous material (a fiber fluorine). Microfiber nonwoven fabrics have essentially excellent properties in removing dirt and in absorbing and releasing liquids, especially water.

However, the disadvantage of known microfibrous nonwoven fabrics is that their durability is limited, especially when washed frequently in industrial wash cycles, which manifests itself in the formation of holes in nonwoven fabrics, for example, after approximately 200 industrial wash cycles.

By increasing the proportion of coarser fibres, the durability of nonwoven fabrics can theoretically be improved, since the chemical and mechanical stability of individual fibres or filaments increases as their thickness increases. However, this comes at the expense of their handling properties.

Increasing the proportion of fine fibers leads to improved handling properties, among other things, by creating a higher number of capillary cavities, improving water absorption capacity, and by reducing the bending rigidity of the individual fiber, thus providing a softer grip. However, such two-dimensional structures are sensitive to tearing force, pilling and, above all, washability, especially washability at boiling temperature, when compared to conventional textile products. First of all, the handling properties provided by microfibers deteriorate significantly over time. separated and stabilized by water jet), after 400 washing cycles according to DIN EN ISO 155797, it was found that the weight per unit area had decreased significantly. A more detailed analysis revealed that the polyamide content had decreased from an initial 30 to 10 percent by weight, while the PET content had decreased less strongly. This result was surprising, since it is known that PET is attacked by bases, such as liquids, whereas polyamide is not. This result can be explained by the fact that the thinner polyamide filaments in the microfilament nonwoven fabric are exposed to more chemical and mechanical stress inside the laundry and are carried out as broken fibers over time. This may also be due to the thinner fiber thickness compared to polyester.

The decrease in PA6 ratio after 500 washes each time is shown in the table below. The remaining polyamide content is determined here by separation with formic acid. The individual samples show the scattering of PA6 decrease.

Table 1: PA6 ratio decrease from 30% at the beginning to 500 washes (60°C): 9 G 9 9 9 % From this experience, it was expected that integrating PIE 8 segments of double the thickness at the existing linear density of PIE 161 would improve mechanical properties and durability, and adding half the thickness segments from PIE 32 would compensate for the lost properties such as comfort and moisture management.

Another way of combining almost opposite properties in one two-dimensional structure is to produce composites from two or more two-dimensional structures. For this purpose, the individual two-dimensional structures can be produced separately and then stitched, bonded, Multi-component spun nonwoven fabrics having a linear density gradient are also known. Thus, EP 1 619 283 A1 describes multi-component spun nonwoven fabrics consisting of at least two polymers forming adjacent surfaces, which are produced from at least one spinning device with standard spinning nozzle openings and are hydrodynamically drawn, laid in two dimensions and further stabilized together as individual layers or in the form of a multi-component composite.

The invention is based on the task of further improving known microfibrous nonwoven fabrics so that they have good mechanical properties, in particular good permanent wash resistance together with good handling properties, good thermo-physiological comfort, pleasant skin sensitivity and appearance, good water management (water absorption and water release, preferably homogeneously) as well as good cleaning efficiency.

EP 1696064 describes liquid-impregnated two-dimensional structures consisting of a combination of separated fibers and/or meltblown fibers with fibers made from thermoplastic polymers. The two-dimensional structures can be monolayered or multilayered, where separated fiber nonwoven fabrics can be present on the outside of the multilayer two-dimensional structures. The two-dimensional structures can be used as cleaning cloths.

Description of the Invention The invention relates to a microfibrous composite nonwoven fabric comprising a first and a second fiber component arranged in alternating layers, wherein the at least one first layer A comprises the first fiber component in the form of composite filaments produced by the melt spinning method and laid down in a fibrous material, said composite fibers being at least partially separated and stabilized into elementary filaments having an average linear density of less than 0.1 dtex, preferably between 0.03 dtex and 0.06 dtex, . at least one layer B is arranged on the first layer A, wherein layer B comprises a second fiber component in the form of fibers having an average linear density of 0.1 to 3 dtex, laid down and stabilized into a fibrous material, at least one second layer A is arranged on the layer B, wherein the microfiber composite nonwoven fabric has the layer structure A(BA)nBA, wherein n = 1 to 20.

The invention also relates to a method for producing such a microfibrous composite nonwoven fabric and to the use of the products obtained therefrom.

The microfibrous composite nonwoven fabric of the invention is characterized by comprising ultrafine microfilaments in synergistic combination with larger fibers.

Here, the two fiber components are present in layers that are arranged alternately, at least relatively, in certain regions according to the cross-section of the microfibrous composite nonwoven fabric.

According to the invention, it has been found that by specifically combining layers of fine and coarse fibers in an alternating arrangement, the mechanical properties and durability can be significantly improved. Thus, the microfibrous composite nonwoven fabric according to the invention shows excellent permanent wash resistance, especially in industrial hot wash cycles that are subject to high loads. Furthermore, the nonwoven fabric, despite its larger fiber content, offers satisfactory usage properties such as good thermo-physiological comfort, pleasant skin sensitivity and appearance, good water management and also good cleaning efficiency.

This result was surprising in the sense that it was expected that the use of filaments with a smaller filament linear density would indeed lead to an improvement in handling properties, but the strength, and especially the durability of the nonwoven fabric, would deteriorate.

Without relying on a mechanism, it is assumed that the good mechanical strength of the nonwoven fabric according to the invention in terms of pilling, abrasion and washing resistance is achieved by high degree of winding of the fine filaments during their production, i.e. during the separation or stabilization process, for example during needle punching and/or water jet stabilization.

According to a preferred embodiment of the invention, the filaments of the first fiber component are, beyond the layers, at least partially wrapped around each other by the fibers of the second fiber component ("tentuce effect"). This effect can be achieved, for example, by first forming a layer composite ABA or larger layer composites, for example a layer composite ABABA, from the filamentous materials of the first and second fiber components, which are not yet stabilized or only pre-stabilized at first, and then performing a separation or stabilization step for the entire layer composite.

In this procedure, the thin filaments obtained during the separation process of the first fiber component are distributed in the Z-direction, i.e. in the direction of the cross-section of the nonwoven fabric. This distribution can cover several layers and leads to a particularly dense interlocking of the individual layers.

Practical experiments have shown that the thinner the elementary filaments, the more they penetrate into other layers.

According to the invention, the first fiber component has composite filaments spun from the melt and laid down into a fibrous material. By filaments, according to the invention, is meant fibers which, unlike staple fibers, have a theoretically unlimited length. Composite filaments consist of at least two elemental filaments and can be separated and stabilized into elemental filaments by conventional separation methods, for example by water jet needle-casting. The composite filaments of the first fiber component are, according to the invention, at least partially separated into elemental filaments. Here, the degree of separation is advantageously greater than 80%, more preferably greater than 90% and in particular 100%.

In order to obtain a sufficient stabilization effect, it is advantageous for the ratio of the first fiber component to elemental filaments to be at least 20% by weight, relative to the total weight of the nonwoven fabric and as a total value throughout all composite layers. Practical experiments have shown that good handling properties, especially with a high wash resistance, can be obtained when the ratio of these elemental filaments is between 20% and 60% by weight, and especially between 30% and 50% by weight, relative to the total weight of the nonwoven fabric.

With regard to the individual layers of the nonwoven fabric, it is advantageous if the elementary filaments of the first fibre component are particularly 100% by weight in the relevant layer A, for example an outer layer A or an inner layer A.

In terms of permanent use properties (pilling, abrasion and washing resistance), it is advantageous here if at least one outer layer of the nonwoven fabric, but advantageously both outer layers, is formed by layers A.

It is possible to assume that the relevant layers A contain other fibers besides the first fiber component. However, surprisingly, particularly good handling properties are obtained when at least the outer layers A consist entirely of elementary filaments of the first fiber component.

The advantage of using composite filaments as starting material for the production of elementary filaments is that the linear density of the elementary filaments produced from them can be easily adjusted by changing the number of elementary filaments contained in the composite filaments. Here, the linear density of the composite filaments can remain constant, which is advantageous from a processing technique point of view. The additional advantage of using composite filaments is that by changing the degree of separation of the composite filaments, the ratio of coarse filaments to fine filaments in the nonwoven fabric can be easily controlled.

Practical experiments have shown that nonwoven fabrics with a high average linear wash resistance and good handling properties can be obtained from the elementary filaments of the first fiber component. This can be achieved by separating the elementary composite filaments with linear density.

The cross-section of the elementary filaments is preferably a microfibrous composite nonwoven fabric in which the composite filaments have a cross-section shaped like an orange slice or a multi-segment structure called "Pie", wherein the segments can contain different, alternating, incompatible polymers. Hollow pie- shaped structures are also suitable, which can also have an asymmetric axially extending cavity. Pie-structures, especially hollow pie- structures, are particularly easy to separate.

In terms of the first fiber component, the orange slice- or pie slice-shaped arrangement preferably has 16, 24 or 32 segments.

The proportion of the first fibre component in the nonwoven fabric is preferably at least 40 wt%, more preferably 40 wt% to 60 wt%, in particular 45 wt% to 55 wt%, relative to the total weight of the nonwoven fabric in each case.

In order to achieve easy separation, it is advantageous for the composite filaments to consist of filaments containing at least two thermoplastic polymers. The composite filaments here preferably consist of at least two incompatible polymers. Incompatible polymers are understood to mean polymers that do not bond when combined, but only form limited or poorly bonding pairs. Such a composite filament has good separation to the basic filaments and provides a favorable strength-to-weight-per-unit-area ratio.

As incompatible polymer pairs, polyolefins, polyesters, polyamides and/or polyurethanes are preferably used in a combination that results in non-adhesive, only limited or poorly adhesible pairs.

The polymer pairs used are preferably selected from polymer pairs consisting of at least one polyolefin and/or at least one polyamide, preferably polyethylene, such as polypropylene/polyethylene, polyamide/polyethylene, or polyethyleneterephthalate/polyethylene, or polypropylene, such as polypropylene/polyethylene, polyamide/polypropylene or polyethyleneterephthalate/polypropylene.

Polymer pairs with at least one polyester and/or at least one polyamide are particularly preferred.

Polymer pairs with at least one polyamide or at least one polyethyleneterephthalate are preferred due to their limited adhesiveness, and polymer pairs with at least one polyolefin are particularly preferred due to their difficulty in adhesiveness.

Polyesters, preferably polyethyleneterephthalate, polylactic acid and/or polybutyleneterephthalate, on the one hand, and polyamide, preferably polyamide B, polyamide 66, polyamide 46, optionally in combination with one or more polymers, preferably chosen from polyolefins, which are incompatible with the above-mentioned components, on the other hand, have proved to be particularly suitable as preferred components. This combination exhibits excellent separability. The combination of polyethyleneterephthalate with polyamide 6 or polyethyleneterephthalate with polyamide 66 is most particularly preferred.

The proportion of the second fibre component in the nonwoven fabric is preferably at least 30 wt%, preferably 40 wt% to 60 wt%, in particular 45 wt% to 55 wt%, relative to the total weight of the nonwoven fabric at each time.

It is conceivable that the respective layers B contain other fibers as well as the second fiber component. Thus, the respective layers B advantageously contain fibers of the first fiber component as well as the second fiber component. These can be inserted into layer B from layers A, for example during stabilization and/or separation. In this way, a higher wrapping of the layers and thus a higher strength can be achieved.

The type of fibres of the second fibre component is essentially not critical if the linear density is between 0.1 and 3 dtex. Thus, the fibres of the second fibre component can be chosen from the group consisting of filaments, staple fibres, yarns and/or threads. Staple fibres are here understood to mean fibres having a limited length, preferably between 20 mm and 60 mm, in contrast to filaments, which theoretically have an unlimited length.

The fibres of the second fibre component can be made of the most diverse materials. In particular, polymers, here above all plastic materials, especially the plastic materials already discussed above in relation to the first fibre component, but also The choice of the fibres of the second fibre component is made according to the relevant fields of use in which the nonwoven fabric will be used. The filaments have proven themselves suitable for a large number of uses. They are available as single-component filaments and/or as composite filaments.

The fibers of the second fiber component are preferably, just like the fibers of the first fiber component, at least relatively present as composite filaments or are at least partially separated into elementary filaments. In this case, at least some of these elementary filaments have a linear density of 0.1 to 3 dtex. Particularly preferably, all of these elementary filaments have this linear density. Such elementary filaments can be obtained by separating composite filaments having a linear density of 0.2 to 24 dtex.

Here, the use of composite filaments also has the advantage that the linear density of the individual elementary filaments can be easily adjusted by changing the number of elementary filaments contained in the composite filaments. In addition, the ratio between the bloody filaments and the fine filaments in the nonwoven fabric can be controlled by changing the degree of separation. Practical experiments have shown that particularly good hairing properties can be achieved when the degree of separation of the composite filaments is set to at least 60%, more preferably at least 70%, more preferably 80% to 100%.

Another advantage is that in this form of application, a stabilization of the nonwoven fabric can be achieved by separating the two composite filament components together, for example by means of water jet stabilization. This procedure allows the elementary filaments formed during the separation to be wrapped around each other particularly intensively beyond the layer, so that the resulting composite nonwoven fabric has particularly good permanent strength.

The type and structure of the composite filaments may be those discussed above for the first fiber component. The composite filaments of the second fiber component preferably consist of 2, 4, 8, 16 elementary filaments and particularly preferably of 4 or 8 elementary filaments.

Alternatively, the fibers of the second fiber component can be a mixture of monocomponent filaments and/or composite filaments and monocomponent filaments.

The average linear density of the filaments of the first fiber component is preferably, according to the invention, significantly below the average linear density of the filaments of the second fiber component.

However, practical experience has shown that, in order to achieve high strength and good handling properties, it is expedient for the fibres of the second fibre component to have an average linear density of not more than twice, preferably not more than ten times, the average linear density of the fibres of the first fibre component.

It has been found to be particularly advantageous if the ratio of the average filament linear density of the filaments of the second fibre to the average filament linear density of the filaments of the first fibre component is between 6 and 16, preferably between 8 and 12. Nonwoven fabrics with such a ratio have been found to have a particularly high delamination resistance.

As already explained above, an important characteristic of the nonwoven fabric according to the invention is the alternating arrangement of layers of fibers with large and small linear density. A placement arrangement in which the filaments from the layers of fibers with small linear density are at least partially inserted into the layers of fibers with large linear density is particularly preferred ("tentacle effect"). In this way, the large filaments located in the inner part, which have low stability due to their low wrapping among themselves, can be provided with maximum protection against the fine filaments located on the outer side, which have good stability due to their high wrapping degree with themselves and the large filaments. At the same time, the thin filaments located on the outside, which, due to their lower mechanical strength and rigidity, have a higher tendency to fuzz (the fibers can be more easily separated from the composite due to mechanical strain), can be better anchored inside the total composite of the nonwoven fabric. This can be achieved, in particular, by the "tentacle effect" mentioned above, which integrates them better into adjacent layers of filaments with a greater linear density.

In light of this background, it is advantageous if at least part of the surface of the nonwoven fabric is formed by elementary filaments with a linear density of less than 0.1 dtex. Accordingly, it is advantageous if at least one, preferably both, of the surfaces of the nonwoven fabric is formed by at least 50%, preferably 60-100%, of elementary filaments with a linear density of less than 0.1 dtex. The structure and composition of the surface can be determined, for example, by REM images.

The advantage of the introduction of fine filaments on the outer side of the nonwoven fabric is that all types of yarns or filaments in the inner side, but especially the large fibers of the second fiber component, can be mechanically stabilized. At the same time, the surface of the nonwoven fabric is characterized by advantageous handling properties and an advantageous element and grip.

The formation of the alternating arrangement of large and small fibers in the composite nonwoven fabric according to the invention can be achieved, for example, by separately producing the layers containing the first fiber component and the layers containing the filaments of the second fiber component and joining them together in the desired arrangement. The joining of the layers can be done by known joining methods such as sewing, gluing, lamination and/or mechanical needle-punching, wherein the individual layers are optionally stabilized.

The joining of the layers with each other is made particularly easy by means of a water jet stabilization of the composite filaments contained in the nonwoven fabric.

Here, it is also possible to pre-stabilize the layers separately before the consolidation process.

Preferably, the fibers of both the first and second fiber components are composite filaments that are at least partially separated into elementary filaments. In this case, a stabilization of the nonwoven fabric is preferably carried out by separating both composite filament components together. This can be done, for example, by first forming a layer composite from the fibrous materials of the first and second fiber components and then stabilizing, for example, by means of water jets. This procedure allows the elementary filaments formed during the separation to be wrapped around each other particularly intensively beyond the layer, so that the resulting composite nonwoven fabric has particularly good permanent strength.

In order to achieve a high degree of wrapping, it is particularly expedient for the degree of separation of the first fibre component to be as high as possible. In light of this background information, the proportion of the respective elementary filaments of the first or second fibre component within the layers is preferably greater than 80% by weight, more preferably 85 to 100% by weight.

In a particularly preferred embodiment of the invention, all layers A contain at least partially separated Pie 24 filaments, Pie 32 filaments and/or Pie 64 filaments. It is also conceivable that all layers B contain at least partially separated Pie 8 filaments or Pie 4 filaments. An arrangement is also conceivable in which one or more layers B contain Pie 8 filaments and other layers B contain Pie 18 filaments and/or Pie 4 filaments.

As already explained above, it has been found to be particularly advantageous to arrange the layers in such a way that layers B, containing the filaments of the second fibre component, are located in the inner part of the nonwoven fabric, while layers A, containing the filaments of the first fibre component, are arranged at least on the surfaces of the nonwoven fabric. In this arrangement, the outer covering layers with fine filaments are able to protect the inner layers more effectively, despite their surprisingly fine linear density and the resulting mechanical stability, which leads to the formation of a particularly robust layer composite and to good long-term handling properties, as explained above.

This effect is probably due to the fact that the fine filaments obtained in the separation process are distributed in the Z-direction, i.e. in the direction of the cross-section of the nonwoven fabric, during the stabilization step. This distribution can cover several layers and leads to a particularly dense interlocking of the individual layers. Practical experiments have shown that the finer the elementary filaments, the more they are carried into the adjacent layers.

The nonwoven fabric according to the invention comprises at least three layers A containing filaments of the first fiber component and at least two layers B containing filaments of the second fiber component. In this way, the alternating basic layer sequence A-B-A is obtained. As already explained above, by integrating layer B into the inner part of the layer composite, a composite nonwoven fabric with excellent permanent strength can be obtained. Since the outer sides of the nonwoven fabric are formed by layers A, the nonwoven fabric also has very good handling properties.

The basic layer sequence A(BA)nBA according to the invention can be expanded with other alternating layers A and B. According to the invention, the microfibrous composite nonwoven fabric has the water layer structure A(BA)nBA, A(BA)nBA, where n = 1 to . Another preferred embodiment of the invention includes water layer sequences: A(BA)nBA, where n = 5 to 15 and particularly 8 to 12. Thus ABABABA, ABABABABA etc. are examples of layer sequences. Here, one or more layer A's can be considered to cover more than one sublayer A' and/or one or more layer B's can be considered to cover more than one sublayer B'. Here, the linear density of the fibers within the respective sublayers may be the same or may differ from each other. In a spinning system with 15 spinning positions, the following arrangement of sublayers A' and B' can thus be considered: A'A'B'B'B'A'B'B'B'A'B'B'B'A'A', which gives the following presentation for the person who later examines the cross-section: A(BA)2BA.

According to a preferred embodiment of the invention, in the layer sequences, the outer layers are each time formed by layers A. Furthermore, the layer sequences are advantageously characterized by an alternating arrangement of layers A and B. However, as explained above, it is also conceivable that the layer sequence has other layers, different from A and B.

It has also been found to be advantageous to design the layer order of layers A and B, as well as any other layers optionally available within the microfibrous composite nonwoven fabric, in such a way that a symmetrical layer structure is formed. This arrangement has the advantage that a particularly homogeneous, side-symmetrical property profile can be achieved.

According to a preferred embodiment of the invention, all layers A and/or B have fibers with the same fiber linear density in each case. These embodiments are advantageous because they allow the nonwoven fabric to be produced particularly easily. However, according to an alternative, preferred embodiment, the different layers A (and/or B) and/or sub-layers A' (and/or B') have fibers with different fiber linear density. The advantage here is that the properties of the nonwoven fabric can be adjusted in a very targeted and side-oriented manner.

The composite nonwoven fabric according to the invention may also comprise other layers. The other layers may be considered as reinforcement layers, for example formed in the form of a scrim, and/or they may comprise reinforcement filaments, nonwoven fabrics, woven fabrics, knits and/or knitted fabrics. Plastic materials, for example polyesters, and/or metals are preferred materials for forming the other layers. Here, it is primarily conceivable that the other layers constitute the outer layers of the nonwoven fabric. However, advantageously, the other layers (optionally additional) are arranged in the inner part of the nonwoven fabric, between layers A and B.

Polymers used to produce composite nonwoven fabric filaments may contain, at least in part, an additive selected from the group consisting of color pigments, antistatic agents, antimicrobial agents, such as copper, silver gold, hydrophilizing - or hydrophobic additives, in an amount ranging from 150 ppm to 10% by weight.

The use of specified additives in the polymers used allows adaptation to customer-specific requirements.

The weights per unit area of the composite nonwoven fabric according to the invention are adjusted depending on the desired purpose of use. When measured according to DIN EN 29073, it has been seen that the weights per unit area are suitable for a large number of uses.

As explained above, the microfibrous composite nonwoven fabric according to the invention is characterized by excellent mechanical properties. Thus, the microfibrous composite nonwoven fabric according to the invention is characterized by a high durability, according to a preferred application of the invention. Thus, it has been determined that the exemplary nonwoven fabrics according to the invention do not exhibit holes even after 850 industrial washing cycles according to DIN EN ISO 155797.

Advantageously, the microfibrous composite nonwoven fabric is also characterized by a tear spreading force that can be easily adjusted according to DIN EN ISO 155797.

Furthermore, the microfibrous composite nonwoven fabric according to the invention is characterized by a well adjustable moisture balance.

The microfibrous composite nonwoven fabric according to the invention can be produced in a shape and form known to the skilled person. A method in which at least a first fiber layer comprising filaments of the first fiber component and at least a second fiber layer comprising filaments of the second fiber component are produced and bonded together has been found to be particularly simple.

In an advantageous manner, the method for producing the composite nonwoven fabric according to the invention is carried out as follows: First, the individual fibre layers are spun separately, laid out into a fibrous material and optionally subjected to a preliminary stabilization treatment, for example by needle punching. The fibre layers are then bonded together. In particular, a preliminary stabilization has been found to be expedient with respect to the layers B arranged in the inner part of the composite nonwoven fabric as described above, since it prevents the fibres of the second fibre component from reaching the surface of the composite nonwoven fabric.

Joining of individual layers can be achieved by known joining methods such as sewing, gluing, lamination, calendering and/or needling.

However, the bonding of the individual layers is particularly preferably carried out by, after their production, arranging layers of fibres of the first fibre component and layers of fibres of the second fibre component alternately on top of each other and then directly stabilising them, for example by mechanical stabilisation and/or hydrofluidisation, and at the same time bonding them to each other.

The composite nonwoven fabric can be stabilized from the outside inwards by a hydrofluidization process, and can optionally be separated and knitted from the inside with larger filaments located on the inside. This procedure allows a particularly effective use of filaments with a low filament linear density, since the fine filaments are transported very deeply into the nonwoven fabric and there, apparently due to their intertwining, lead to a particularly effective stabilization of the composite, the "tentacle effect". The stabilization and separation of the fiber layers is advantageously carried out by treating the nonwoven fabric composite, which has optionally undergone a pre-stabilization treatment, at least once on all sides with high-pressure fluid jets, preferably high-pressure water jets. The composite nonwoven fabric according to the invention can thus obtain the appearance of a textile surface and the degree of separation of the composite filaments can be set to over 80%.

It is also possible that the fibers of the first and second fiber components come from a standard spinning and/or laying process, are produced simultaneously and laid together. For this purpose, at least two spinning stations with standard spinning nozzle openings can be provided, each of which produces composite filaments with different numbers of elementary filaments or a mixture of composite filaments and single-component filaments in a common spinning and drawing device. These filaments can then be laid down to form the composite nonwoven fabric according to the invention and can also be stabilized by hydrofluidization and separated into elementary filaments.

With this, the advantage is that the production of spun nonwoven fabrics with different filament linear densities does not have to be done separately and that a disadvantageous joining process is not required to achieve a multi-component spun nonwoven fabric consisting of different filaments with different filament linear densities.

According to a preferred embodiment of the invention, at least three, preferably at least five, rows of spinning heads are provided, each with standard spinning nozzle openings, which produce composite filaments with different numbers of elemental filaments or a mixture of composite filaments and monocomponent filaments in a common spinning and drawing device in each run. Alternatively, at least one row with suitably different spinning nozzle openings can be provided as a spinning nozzle package (curtain spinning) or as a plurality of individual spinning nozzle packages, in a traverse arrangement.

These can then be laid down to form a fibrous material and can also be stabilized by hydrofluidization and separated into elemental filaments. A mechanical or thermal pre-stabilization process may be foreseen prior to hydrofluidization. According to this application, composite nonwoven fabrics can be obtained, which consist of layers with a different filament linear density and thus combine the textile-physical properties that could otherwise be obtained only by combining layers produced separately.

Advantageously, the method according to the invention is further developed in such a way that the order of the spinning stations according to the laying belt can be obtained in an ABA or A(BA)nBA arrangement of the composite layers, the above mentioned layer structures.

According to a preferred embodiment of the invention, the order of the spinning stations relative to the lay-up belt is chosen in such a way that a linear density is created alternating throughout the thickness of the composite nonwoven fabric.

As explained above, composite filaments may have a central opening, which may be in the form of an elongated cavity, especially a tubular one, centered relative to the mid-axis of the composite filaments, to facilitate separation into elementary filaments. With this arrangement, the close contact between the elementary filaments, created by the internal angle of the columns or circular sections, can be reduced or prevented before the elementary filaments are separated, as well as the contact in this region of several elementary filaments made of the same polymer material.

For further stabilization of the composite nonwoven fabric framework, the composite filaments may have a latent or spontaneous tortuosity, which consists of an asymmetrical structure of the elementary filaments with respect to their longitudinal median axis, where this tortuosity is optionally activated or reinforced by an asymmetrical, geometric design of the cross-section of the composite filaments. Thanks to this, the nonwoven fabric can be provided with a high thickness, a low modulus and/or a multiaxial elasticity.

In a variation, the composite filaments may have a latent or spontaneous curvature, which is due to the physical properties of the polymer materials constituting the elemental filaments being altered during the spinning, cooling and/or extension processes involving the composite filaments, leading to torsions resulting from internal, asymmetrical stresses with respect to the longitudinal median axis of the composite filaments, where the curvature is optionally activated or reinforced by an asymmetric, geometric design of the cross-section of the composite filaments.

Composite filaments may have a latent curl that is activated by thermal, mechanical or chemical treatment before the composite nonwoven fabric is formed.

The curling can be reinforced by an additional treatment, e.g. thermally or chemically, prior to the stabilization of the nonwoven fabric. The stabilization of the fibrous material according to the invention is preferably carried out by treatment with high-pressure fluid jets. In this way, the elementary filaments can be strongly wound by a mechanical, largely perpendicular means to the plane of the fabric (needling, liquid pressure jets) during or after the separation of the composite filaments.

Filaments, especially composite filaments, can be laid down, for example, by mechanical and/or pneumatic deflection, where at least two of these types of deflection can be combined, and can also be laid down on an endless moving belt by means of winding and mechanically by needle-punching or by acting with liquid pressure jets to which solid (micro) particles have been applied. The steps of winding the composite filaments and separating them into elemental filaments can be carried out in one and the same process step and with one and the same equipment, where the more or less complete separation of the elemental filaments can be completed by an additional, rather separating operation.

The strength and mechanical resistance of the composite nonwoven fabric can also be significantly increased if the elemental filaments are bonded to each other by means of thermal fusion involving one or more of them, preferably by hot calendering with heated, flat or engraved rollers, by passing through a hot air tunnel oven, by passing through a drum through which hot air is passed and/or by applying a binder contained in a dispersion or a solution or in powder form.

In a variation, a stabilization of the fibrous material can again be achieved, for example by hot calendering, prior to any separation of standard composite filaments into elemental filaments, where the separation is carried out after the stabilization of the fibrous material.

Furthermore, the fibrous material framework can be stabilized by a chemical treatment (as described, for example, in the applicant's French patent no. 2 546 536) or a heat treatment, which causes at least some of the elementary filaments to shrink in a controlled manner, after their optional separation. As a result, the fabric shrinks in the width and/or length direction.

In addition, the composite nonwoven fabric may be subjected, after stabilization, to a chemical type of bonding or finishing treatment, such as an anti-pilling treatment, a hydrophilizing or hydrophobic treatment, an antistatic treatment, a treatment to improve fire resistance and/or to modify tactile properties or gloss, a mechanical type of treatment such as roughening, sanforizing, sanding or a treatment in the drum and/or a treatment to modify the appearance, such as coloring or printing.

Practical experiments have shown that when the fibrous material is pre-stabilized by applying heat and/or pressure to it, preferably by calendering at 160°C, a composite nonwoven fabric with a particularly homogeneous structure can be obtained.

The composite nonwoven fabric according to the invention is advantageously subjected to a point calendering process to increase its abrasion resistance. For this purpose, the separated and stabilized composite nonwoven fabric is passed between heated rollers, at least one of which has elevations that cause the filaments to melt together pointwise. According to a preferred embodiment of the invention, the composite filaments are colored by spinning coloring.

The microfibrous composite nonwoven fabric according to the invention is perfectly suited for the production of the most diverse textile products, especially those that must be thermo-physiologically comfortable and, in addition, decorative and, moreover, must be characterized by a particularly high and permanent wash stability. This includes, first of all, laundry items such as tablecloths, bed linens and pillowcases, bed linens and pillowcases, especially those used in hospitals and/or nursing homes, sanitary products such as bathrobes, hand towels, patient linens. The microfibrous composite nonwoven fabric according to the invention is particularly suitable for the production of products belonging to the product range of rental laundries, thanks to its particularly permanent wash stability.

The use of the microfibrous composite nonwoven fabric according to the invention for the production of rental laundry is thus another subject of the present invention. In this use, the advantage of long durability is particularly evident in the nonwoven fabric, since it actually leads to a longer reinvestment cycle. Long durability allows users to use textiles in which the consumption of raw materials can be reduced thanks to very long use. The nonwoven fabric according to the invention thus also constitutes a product with improved sustainability.

The invention is explained in detail below with the help of several examples. Examples 1 to 12: Production of various nonwoven fabrics layers are formed, they have the following composition: (01) 130 16 (02) 130 8 (03) 130 32 Here, the nonwoven fabrics 7, 8, 9 and the composite nonwoven fabrics according to the invention are obtained.

For the production of nonwoven fabrics, in a first step, nonwoven fabric layers consisting of PIE 16, PIE 8 and PIE 32 segmented bicomponent filaments are produced.

Below, the production of PIE 32 in a bicomponent fibrous material spinning system is described as an example.

The following raw materials are used: Granules Ratios PES PET INVISTA 50 Poly-Amid PA6 BASF 50 Hydrophilic (PET) in CLARIANT PET 0.05 TiO2 CLARIANT Renol white in PET 0.05 Antistat agent (PA6) in CLARIANT Hostastat PA6 0.05 Extruder: PET, zones 1 - 7: 270-295 °C PAG, zones 1 - 7: 260-275 °C Spinning pumps: Volume, speed, in hand, PET: 20cm3/rev, 9.1rpm, 0.35 g/L/min g/L/min Total in hand: 0.79/L/min Nozzles: Type, PlE 32, Pneumatic traction A placement belt with a set speed, with which a weight of fibrous material per unit area of 22 or 43 g/m2 is obtained.

Calenders, pre-stabilization by means of plain/flat steel materials: The structure of the resulting PlE 32 segmented bicomponent filaments is shown in Figure 1.

To produce composite fiber materials, layers are stacked in the desired order. The individual layers are then separated and felted by water jet stabilization to form a multi-filament composite nonwoven fabric.

Since the same target weight is targeted for all composite variations (approximately 100%), a definitive test guideline for water jet stabilization is chosen for all variations, regardless of the subject.

The water jet conditions are set as follows: Pressure (bar) Suction (mbar) Preliminary stabilization: 0.4 -728 Pressure (bar) Suction (mbar) Düze bar 2: 2.8 - 74 Düze bar 3: 230 -206 Düze bar4: 0.1 -206 Düze bar 5: 230 -871 Düze bar 3 and 3 are opposite each other.

Nozzle strip hole diameter: 130um Locating belt: 100 mesh Material conveying speed: 12 m/min Passage repetition: 2x (i.e. 3 passages in total) Drying conditions are set as follows: A drying is carried out in a ventilated dryer of approximately 4 m length at an air temperature of 190 ° C and a belt speed of 12 m/min.

In water jet stabilization, the two-component filaments are almost completely separated into the corresponding elemental filaments. At the same time, the thin PIE-32 elemental filaments of the outer layers are transported deep into the nonwoven fabric and are there wrapped both among themselves and with the thicker PIE-8 or PIE-16 elemental filaments (tentacle effect), which surprisingly leads to a particularly high durability of the composite nonwoven fabrics according to the invention 7, 8, 9. In addition, the nonwoven fabrics according to the invention show excellent handling properties, such as good thermo-physiological comfort, pleasant skin sensitivity and optical properties, thanks to the outer layers consisting of very thin PIE-32 elemental filaments. Thanks to the inner layers consisting of thicker filaments, 0 also offers excellent water absorption capacity and tear spread resistance. Example 13: Testing of various parameters of nonwoven fabrics The tests are based on the following standards: FG Weight per unit area EN 965 Thickness (mm) HZK Maximum tensile At maximum tensile force Module (N) Porosity (pm) WRK Tear propagation Abrasion (Martindale, force 9KPa) Air permeability (l/mZ/s) Pilling (Degree) Water absorption (%) Industrial type laundry (here 75°C) EN 964-1 EN 13934-1 EN 13934-1 EN 13937-2 EN 12947 EN 9237 DIN 53867 (based on) DIN 53923 DIN EN ISO 155797 (number of cycles until a hole is formed) The results of the tests performed are shown in the following tables: Textile - Physical Analysis N° 1 2 3 FG 3 13 3 target (glmz) 07 I 015 0.5 5 °C at 400mmlmn' dynamometer 33 17 26 29 breaking length 65, 54, Module length before Martin 18 12128 26 19291 14.9 7 13.6 4 6*7 8* 14 13 108 101 99 28 20 19 165 169 171 56 46 44 280 301 311 118 114 114 6.7 - - .2 7.9 8.5 9.2 13.5 13.7 13 140 94 18 206 154 41 433 271 97 102 11 12 12 14 11 6 0.8 17 20 15 2 1.1 6 8 158 41 35 4 7 275 - - 11, 11, 12, 3, 6 8 6 NA ination (N/5c N permeability1 (1/m2/ Plumage 4, After boiling washing (95°C) In the analysis of the results in Table 3, it was found, firstly, that in all the subjects consisting of PIE-32, especially high washing resistances were recorded, whether completely or externally. This is surprising, since it was not expected that the thin filaments would show good mechanical strength. However, the cloths consisting entirely of PIE-32 are only suitable for use to a limited extent, because they have, among other things, a very low tear spread resistance. In contrast, the composite nonwoven fabrics according to the invention are characterized by both satisfactory tear propagation and maximum tensile strengths and good washing resistance. From the table, it can also be seen, surprisingly, that in the reference samples, the abrasion resistance increases disproportionately as the linear density decreases. Example 14: Testing the cleaning properties of nonwoven fabrics The nonwoven fabrics were tested for their water absorption and water release.

They have also been subjected to the wax chalk test.

Cleaning properties, Water balance Example 15: Testing the results of continuous washing of nonwoven fabrics Property Water uptake Water discharge 1x Wax chalk The test samples were automatically washed one after another, stopping after every 50 washings for evaluation and washing until a hole formation was noticed. The wash is then finished: Test sample Number of cycles until holes are formed Test sample Number of cycles until holes are formed N° 9 550 N° 10 350 Example 16: Visual inspection of nonwoven fabrics Figures 2 to 6 show photographs of the surfaces of representative nonwoven fabrics.

Figure 2 shows the surface structure of the nonwoven fabric N0.2 according to the invention after 250 washing cycles. It is seen that the surface is very rough and has a high degree of pilling.

Figure 3 shows the surface structure of the non-woven fabric N0.1 according to the invention after 250 washing cycles. Although the surface has an improved visual appearance compared to the non-woven fabric N0.2, it is still rougher and has a high degree of pilling.

Figure 4 shows the surface structure of the nonwoven fabric No. 3 according to the invention after 250 washing cycles. The surface has a significantly improved visual appearance compared to the nonwoven fabric No. 02. However, as already mentioned above, the nonwoven fabric consisting entirely of PlE-32 is only suitable for use to a limited extent because, among other things, it has a very low tear propagation strength.

In Figure 5, the surface structures of the inventive nonwoven fabric No. 7 after 500 wash cycles are compared with the non-inventive nonwoven fabrics 1 (after 650 wash cycles) and 3 (after 800 wash cycles).

The surface of the nonwoven fabric No. 7 according to the invention is seen to have a good visual appearance, similar to the nonwoven fabric No. 3 consisting of only PlE-32. Furthermore, it is characterized by excellent handling properties, such as good water management, a high tear strength, a good degree of pilling and good cleaning properties. In comparison, the nonwoven fabric 1 according to the invention exhibits a strong hole formation.

A cross-section of the nonwoven fabric No. 7 according to the invention is shown in Figure 6. The "tentacle effect" can be clearly seen, where the thin PIE-32 elements are transported deep into the larger filament layers by water jet stabilization.

Claims (15)

REQUESTS Microfibrous composite nonwoven fabric comprising a first and a second fibre component arranged in alternating layers, wherein: - at least a first layer A comprises the first fibre component being in the form of composite filaments produced by the melt-spinning method and laid down into a fibrous material, said composite fibres being at least partially separated and stabilised into elementary filaments having an average linear density of less than 0.1 dtex, preferably between 0.03 dtex and 0.06 dtex, - at least one layer B is arranged on the first layer A, wherein layer B comprises the second fibre component being in the form of fibres having an average linear density of 0.1 to 3 dtex, laid down and stabilised into a fibrous material, - at least one second layer A is arranged on the layer B fabric, layer structure with n = 1 to 20 A(BA)nBA. Microfibrous composite nonwoven fabric according to claim 1, characterized in that the composite filaments of the first and/or second fiber component are orange-shaped or Microfibrous composite nonwoven fabric according to one or more of the above claims, characterised in that the pie-arrangement of the first fibre component has 24, 32, 48 or 64 segments. Microfibrous composite nonwoven fabric according to one or more of the above claims, characterised in that the composite filaments comprise different filaments containing at least two incompatible polymers. Microfibrous composite nonwoven fabric according to one or more of the above claims, characterised in that the second fibre component comprises composite filaments, preferably consisting of 2, 4, 8, 16 elementary filaments and particularly preferably consisting of 8 elementary filaments. 6. Microfibrous composite nonwoven fabric according to one or more of the preceding claims, characterized in that the ratio of the average filament linear density of the filaments of the second fiber component to the average filament linear density of the first fiber component is 10 to 30. 7. Microfibrous composite nonwoven fabric according to one or more of the above claims, characterized in that the proportion of filaments of the first fiber component is 20-60% by weight, preferably 30-50% by weight and in particular 35-45% by weight, relative to the total weight of the nonwoven fabric in each case. 8. Microfibrous composite nonwoven fabric according to one or more of the above claims, characterized in that the proportion of filaments of the second Fibre component is 40-80% by weight, preferably 50-70% by weight, in each case relative to the total weight of the nonwoven fabric. 9. Composite nonwoven fabric according to one or more of the preceding claims, characterised in that the composite nonwoven fabric has a surface formed by elementary filaments of the first fibre component. 10. Microfibrous composite nonwoven fabric according to one or more of the preceding claims, characterized in that a layer ordering A(BA)nBA is present, with n = 1 to 15, wherein layers A contain at least partially separated Pie 32 filaments and layers B contain at least partially separated Pie 8 filaments, wherein the linear density of the elemental filaments of the Pie 32 filaments is less than 0.1 dtex and the linear density of the elemental filaments of the Pie 8 filaments is 0.1 -3 dtex. 11. Microfibrous composite nonwoven fabric according to one or more of the preceding claims, characterised in that at least one further layer, preferably designed as a reinforcing layer, e.g. scrim, is arranged between layers A and B. 12. Microfibrous composite nonwoven fabric according to one or more of the above claims, characterized by a symmetrical layer structure. 13. A method for producing a microfibrous composite nonwoven fabric according to one or more of the preceding claims, comprising the following steps: - at least three fibre layers A comprising filaments of the first fibre component and at least two fibre layers B comprising filaments of the second fibre component are separately spun, laid down into a fibrous material and optionally, for example, pre-stabilised; - fibre layers A and B are alternately arranged on top of each other, wherein the outer layers are formed by fibre layers A; - the layer composite is subsequently subjected to a hydrofluidisation treatment, wherein a separation of the first and optionally also a second fibre component is carried out, wherein the layers A and B are stabilised both within themselves and between themselves. 14. Use of a microfibrous composite nonwoven fabric according to one or more of the preceding claims for the production of tablecloths, bed linens and pillowcases, in particular bed linens and pillowcases used in hospitals and/or nursing homes, sanitary products, e.g. bathrobes, hand towels, patient linens. 15. The use according to claim 14, for the production of rental laundry.